| Specification | Period | N | Countries | R² | Z_1 | Z_2 | Z_3 |
|:-------------|:-------|---:|----------:|----:|----:|----:|----:|
| Pre-China WTO Accession | <2001 | 1,407 | 163 | 0.106 | 23.73 | -3.25 | 0.12 |
| Post-China WTO Accession | >=2001 | 3,925 | 177 | 0.228 | 17.47 | -1.65 | 0.04 |
| Pre-Global Financial Crisis | <2008 | 2,581 | 171 | 0.112 | 27.81 | -2.74 | 0.07 |
| Post-Global Financial Crisis | >=2008 | 2,751 | 177 | 0.223 | 10.79 | -0.72 | 0.01 |
| Pre-Trump Tariffs | <2018 | 4,282 | 176 | 0.110 | 18.92 | -1.84 | 0.05 |
| Post-Trump Tariffs | >=2018 | 1,050 | 176 | 0.192 | -8.12 | 1.78 | -0.09 |

*Notes:* Pooled GLS with AR(1) correction. None of the Z coefficients are individually significant at conventional levels in either sub-period; formal interaction tests (Z x post_break) yield no significant coefficients for any of the three breaks. Controls: fiscal balance, KAOPEN, expected growth, NFA/GDP, relative output per worker, life expectancy.
